[4] He gained his nickname of "Commodore Decatur" by claiming to be a nephew of the Naval hero of the War of 1812.
In 1859 he abandoned his second wife and their child when he moved to Colorado Territory, where he lived in various towns for the remainder of his life.
He was counted as the second of eleven children, because his twin brother William was born a few minutes earlier.
Sarpy was also important to early Nebraska development, attracting residents and settlement near such posts.
He has been described as a "highly educated man who claimed he was a nephew of Commodore Stephen Decatur, Naval hero of the War of 1812.
The other incorporators included Thomas Whiteacre, T. H. Hineman, George Mason, and Herman Glass.
He died June 5, 1888, in Rosita, Colorado, a small camp in the Sangre de Cristo Mountains.